Method of preparing food products



Aug. 12, 1930. c. BIRDSEYE METHOD OF PREPARING FOGD PRODUCT:

Filed June 18, 1927 5 Sheets-Shee NW-Mm ATTORNEY w m R M 0 w m n w QM. an mm.

W NM. 2. hm an BY W H o L m N W Q 3. km u a mmi f an 3 Q 2mg Aug. 12, 1930. c. BIRDSEYE METHOD OF PREPARING FOOD PRODUCTS Filed June 18. 1927 5 Sheets-Shed. 2

O g i W T N MN MW aw m .NN a. QW Q *R NH Q h M ATTORNEY 2, 1930. c. BIRDSEYE 1,773,079

METHOD OF PREPARING FOOD PRODUCTS Filed June 18, 1927 5 Sheets-Sheet 5 ATTORNEY Aug. 12, 1930. c. BIRDSEYE- 1,773,079

METHOD OF PREPARING FOOD PRODUCTS Filed June 18, 1927 SSheets-Shee 4 Fig.6

/Nl/[NTOR WEW BY mnfi 'ATTOEIVEY Aug. 12, 1930. c. BIRDSEYE 1,773,079

umnon 01-" PREPARING FOOD PRODUCTS Filed June'lB. 1927 5 Sheets-Shani 5 z I f /Nl EN7'OR.' WQW BY ATTbR/VEY Patented Aug. 12, 1930 UNITED STATES PATENT. OFFICE CLAY-OE BIB-DB1", OI GLOUCESTER, MASSACHUSETTS, 'ASBIGHOB, BY mm: AS- SIGHKENTB, TO FBOSTED FOODS OOHPARY, INC 0] DOVER, DELAWARE, A COB- POM'IION OI DELAWARE METHOD OF PREPARING FOOD PRODUCTS Application filed June 18, 1887, Serial No. 199,698,

My invention relates to methods of treating food products by refrigeratin the same, preferably by uick freezing t e product into a frozen 1021:, in which the pristine qualities and flavors of the product are retained for a substantial period after the block has been thawed. In so far as this application contains subject matter disclosed in the applications mentioned below, this application is a continuation in part of m pending applications, Serial No. 40,726, led July 1, 1925; No. 122,070, filed July 13, 1926; No. 156,277, filed December 22, 1926; and No. 169,211, filed February 18, 1927, as a division of Serial No. 156.277.

My invention has especial value in its application to such comestibles as fish and meat, fresh or cooked, and I will describe the invention as ap lied thereto, as an example of its utilit an advantages, although my invention 18 not limited in its application to an particular class of comestibles or food prod ucts.

A method of freezing which requires more than a very short s ace of time for freezin impairs the natura qualities and flavors 0 comestibles. In the case of fish or meat, for instance, slow freezin disrupts the cells of the animal tissue, wit loss of the pristine qualities and flavors and rapid deterioration after thawing. Byl my new method, I am able, by means whic are economical and commercially practical, not only to effect any desired degree of refrigeration but to quick freeze a comestible into a compacted frozen block, having comparative] few air spaces in which the pristine qualities and flavors o the comestihle are retained and remain unimpaired for a substantial period after the block has been thawed. Also, I am able to roduce such a quick frozen block, frozen in t e package or container in which it is to be marketed. Furthermore, I am enabled to quick freeze the product into the desired block by the use of freezing fluids, without any direct contact between the fluid and the package or article being frozen.

My invention constitutes a novel departure in methods of preparing and marketing food products, and, so far as I am aware, has for and in Australia and flew Zealand July 1!, use.

the first time produced as a practical, commercial article of commerce, a compacted quick frozen block of comestibles, preferably frozen in the package in which it is to be marketed, which frozen block can be stored for a lon period of time and transported and marketed at a distance, and then, after being thawed, reassumes its original condition as before freezing. These results and advantages, together with others which will subsequently ap ear, are effected by my new method.

s a preferred way of preparing a block of frozen, dressed fish, for instance, by my new method, I first form the fish into a compact block or slab, thereby consolidating it and freeing the mass of air as much as possible. The less the air, the more rapidly and eflicaciously the block may be frozen, and the less the bacteria held in the frozen block. Preferably, the block is encased in the wraper or carton in which it is later marketed. t is an advantage to make the block comparatively thin, because it is more readily frozen throughout its mass.

I next freeze the block of fish so rapidl and at such a low temperature that the cel s of the fish tissue are substantiall unbroken, whereby the pristine qualities an flavors are retained and persist for a substantial time after thawing. Indeed, when KZ-epared in this manner, the food product a r thawing returns substantially to its original condition, as if it had never been frozen.

As an example of quick freezing by the application of my new method, I have attained excellent results in the treatin of raw fish and meat, by acking the food 111 a rect lar carton, the mass being about two inc ies thick, thus producing a block coniaratively free of air, and squeezing the block tween metal plates, which may be and pref-' erably are in the form of opposed im rforate conveyor belts and simultaneous y quick freezing the packaged blockby maintaining the metal plates at a temperature of 20 to below 0 The block will be completely from in about one hour and one quarter. Bly squeezing the block between the metal p ates, the block is compacted, any unevennesses are flattened out so that the product presents flat surfaces of substantial area immediately juxtaposed against the sides of the carton with which the metal plates are in contact. This insures a minimum of insulating air layers or spaces and a heat conductive contact over a substantial portion of the surface area of the block with conduction of heat fre'm at least two sides of the compressed block, which insures uniform and complete freezing in the minimum of time. Preferably I maintain the plates at the desired temperature by applying a. cooling fluid thereto, and at the same time rovide means whereb the fluid cannot itsel come in contact wit the ackage. When the ackage has remained in reezing contact wit the plates a suflicient period of time, it is withdrawn and is ready for marketing. It can be stored for a long 7 period of time, and transported and marketed at a distance, and then, after being thawed, will be found in its original condition as before freezing in that the natural qualities and flavors of the original food are retained and the product will not desiccate or decay an more rapidly than the original product be ore freezin I will now describe an exam le of a preferred process of treating certain food products in accordance with my new method and will describe the process in connection with a novel form of apparatus which I have devised and which preferably is used in practicing the method although it will be understood that other means and forms of apparatus may be used.

Referrin to the accompan ing drawings, in which li e numerals of re erenoe indicate similar parts throughout the several views;

Figure 1 is a perspective view of an apparatus, constructed in accordance with my invention, looking at the front or feed end thereof (in this view the cover is removed from the freezing chamber of the nearer machine and the spray pipes for the upper conveyor are not shown) Figure 2 is a side elevation partly in longitudinal section of the feed end and central portions of said apparatus;

Figure 3 is a side elevation in continuation of Figure 2, showing the discharge end of the.

apparatus;

Figure 4 is a perspective view of the package receiving trough at the discharge end of the apparatus;

Figure 5 is a cross-sectional view, partly in end elevation, as upon line 55 of Figure 2;

Figure 6 is a cross-sectional isometric view at the discharge end of the freezing chamber;

Figure 7 is a perspective view of a completed package prepared in accordance with my invention;

Figure 8 is a horizontal cross-sectional view of said package immediately beneath the cover;

Figures 9 and 10 are cross sectional views on lines 99 and 10-10 respectively of Figabove which is an n per belt conveyor 2;

The article to be refri erated, shown in the drawing as a food pro uct packed in cartons 3, preferably of substantially uniform height, is carried from one end of t e machine to the other between the upper reach of the lower conveyor 1 and the lower reach of the upper conveyor 2. It is to be understood that said conveyors each pass around a propriate drums or wheels 4, so as to provi e for continuous 0 that the ower reach of the upper conveyor and the upper reach of the lower conveyor are both moving at substantially the same speed in the same direction. As the apparatus is preferably constructed, the upper conveyor is shorter than the. lower conveyor, thus afl'ording accommodation at the end at which the article is introduced, to deliver said article to the lower conveyor without interference by the upper conveyor. After said article has been delivered to the lower conveyor, it then passes beneath the upper conveyor and in contact with both conveyors. The particular apparatus shown in the drawings, and more especially in Fi re 1, is a double machine, that is, one in which there are two pairs of conveyors, but this may be altered to employ only one pair or as many as found necessary or desirable. The two pairs of conveyors are duplicates and from this point on I will refer to and describe the machine as if consisting of only one pair.

The a paratus furthermore includes a suitable ramework 5 and adjustable bearin s 6 at the feedend of the machine for the ax e 7 of the wheel 4 for each conveyor, with tightening means 8 by which proper tension may be applied to the conveyors. The conveyors are preferably actuated simultaneouslyfrom a source of power, such as a motor 9 (see Fig. 3), through appropriate drive means. As shown, said motor actuates a worm 10 herein illustrated as upon the motor shaft. Said worm is in mesh with a worm wheel 11 at the u er end of a vertical drive shaft 12. On sai vertical drive shaft are worms 13 and l tfor the upper and lower conveyors respectively, up or worm 13 being in mesh with a worm whedi 15 on the axle 16 for the driving wheel or drum of the upper conveyor, and the lower worm 14 is in mesh with a similar worm wheel 17 on the axle 18 for the driving drum of the lower conveyor. Both conveyors will therefore be. actuated at the same speed by utilizing worms and worm wheels of the same size and character.

ration in one direction, and also The n conveyor is preferabl arranged to have d v ertical adjustment, this ad'ustment being substantially the same at th ends of the machine as shown. The framework includes two pairs of vertical guide rods or slideways 19 at each end of the machine, the four guide rods at each end of the machine supporting two vertical] adj ustable housings or riders 20, and said ousings or riders providing a propriate bearings at opposite sides for t 1e axle of the conveyor drum. At the drive end of the machine each housing 20 includes a gear case 21 for the upper worm 13 and its worm wheel 15. The drive shaft 12 and worm 13 have a slidln slot and key engagement 22 of a usual kin so that as the housing 20 is moved up and down there will be no interference with the operation of said worm and its worm wheel. Vertical adjustment of each housing as a whole is obtained b means of vertical screws 23 at each side of the said housing and 0 erated through bevel cars 24 (Figs. 1 an 5) on the up er end t ereof in mesh with cooperating evel gears 25 on a horizontal cross shaft 26, which in turn has an ap ropriate operating arm 27 on the outer end thereof. The structure and support for the upper ad- 'ustable conveyor and the drive means for 0th conveyors is such as to afford ready adjustment and a constant driving of the two conveyors in perfect synchronism.

The lower reach of the upper conveyor an the upper reach of the lower conveyor pass longitudinally through a suitable chamber 28, the walls of which are of heat insulating construction so as to conserve the coolin medium as much as possible and also to aid in the ra pidity with which said medium may affect its purpose. Said chamber 28,has appropriate removable top cover 28'. Running through said chamber 28 are lon itudinal tracks or supports located beneath t e edges of the conveyors, the sup orts for the up r conveyor being more ful y described be ow, and the supports for the lower conve or being desi nated by numerals 29, 29 (bigs. 5 and 6 These supports 29, 29 extend longitudinally under the upper reach of the lower conveyor in a horizontal plane and close enough together to permit a considerable pressure to be applied to the conveyor or belt without bending or 'flexing the same.

Support for the lower reach of the upper belt is herein shown as comprising a pair of channel irons 30,30, which run parallel to each other, and substantially under the lon itudinal edges of said belt as shown in i 6. Along the longitudinal upper margin 0 the side wall of each of said channel irons, I adjustably secure an angle iron su port 31, with its depending flange frictionall y held to the channel iron 30 at intervals by clips 32, thus enabling the upper flange of'support 31 to be adjusted quite accurately in a longitudinally horizontal position, even though channel irons-30, 30 may sag or otherwise be out of true horizontal alignment. The said upper flange of support 31 projects inwardly over the top of said channel iron support 30.

Preferably the juncture between the vertical and horizontal flan es of said angle iron 31 is rounded or curved rather than angular, and on this curved edge and projecting inwardly over the an le iron is secured a resilient or spring meta strip 33, here shown as faced with a stri of fabric 34. The parts are so positione and related that the margin of the lower reach of the up er belt will rest upon the upper margin of t e facing strip 34 and, by its own weight or the applicatlon of additional weight, be made to depress the facing strip and spring strip, thus securim constant contact irrespective of irregularities in the belt or support therefor.

The supports are so arranged that liquid on the upper conveyor in flowing off the side edges thereof will be carried also over the outside of said facing strip 34 and on the outside of support 30 and thence drop downwardly past said support 30, which extends below the plane of the lower conveyor, thereby preventing said liquid from entering between said conveyors. The close engagement of the underside of the belt with the fabric strip 34 will prevent the freezing li uid from creepin along the under side of t e upper belt an thus gaining access to the space between the belts. As an added precaution, I have shown an apron 35 secured on the inside of the channel support 30 and depending therefrom substantially to the bottom of the chamber 28 to prevent vapor or splash from the upper belt in any way gaining access to the space between the belts.

The weight of the lower belt, to which is added the weight of the articles being frozen, and the pressure of the upper belt, makes a liquid tight contact between the lower belt and its supporting members'29 which prevents the freezing liquid assing beyond these edge supports and there getting into the space between the belts. l may also secure an apron 35' to the outside edges of the outside supports 29 and depending therefrom approximately to the bottom of chamber 28 to further prevent liquid, vapor or splash from the lower belt in any way gaining access to the space between the belts. If desired, the aprons 35 and 35' may extend to and make a seal with the bottom of chamber 28 to further avoid any vapor from a freezing li uid gaining access to the space between the Its.

By the means just described, I am enabled to use a cooling solution WhlCh would adversely affect the product to be refrigerated if it should come in contact therewith.

The conveyors which I use are preferably imperforate metal belts which shield the artic e being frozen from any freezing fluid which is being used, and yet the arrangement is such as to enable the conveyors to be in direct contact with the article so as to obtain ra id cooling thereof by conductivity. It may e here noted that the prevention of contact between the freezing liquid and the article being frozen is further aided by employing an upper conveyor of greater width than the lower conveyor.

In the preferred construction of apparatus, the channel supports 30 are carried by hangers from riders or housings 20 so as to be moved u and down with said housings when an adyustment for a different sized article is desired. In carrying out this feature of the invention, the supportin channels 30 are shown as projecting from t e end of the refrigerating chamber to a position between the several vertical guide rods at both ends of the machine. Since support for each end of each channel iron 30 is b similar means, onlyone suchsupport willbe escribed. On the outside of the channel 30, substantially parallel thereto, is a lower bar 36 forming part of said hanger. This bar 36 is shown attached at a central point by a bolt 37 and bracket 38 to said channel support, and at each end of said bar is secured a strap 39 which depends thereto from the previously described housing or rider 20, this support being efl'ected through the agency of a cross rod 40 (Fi 5) extending across from one of such ri ers to the other. Each end of each cross rod 40 is adjustably mounted on the rider by being secured to a cleat 41 havin elevating set screws 42 at its corners whic rest upon the to of the rider for raising said cleat to an desired position. Lateral movement of said cleat is prevented by central vertical studs 43 which are slidable through the cleat and which roject upwardly from a fixed position in t e rider. B this means, the channel supports 30 may independently adjustedwith respect to the upper belt wheels.

Suitable spray pipes 44 are arranged above the lower reach of the up er conveyor and below the upper reach of t e lower conveyor within the chamber 28. In the present showing, these spray pipes are shown in longitudinal sections, with a feed pipe 45 leading to each section, so as to secure an adequate spray under proper pressure of the cooling fluid or medium. Where the fluid is li uid, it is desirable to drain the same 05 an re-use it, so I have shown the bottom-of said chamber as sloping and leading to a suitable drain pipe 46 by which roper disposal of the fluid may be made. f the aprons 35 and 85' ake a seal with the floor of chamber 28, additional drain pipes should be used.

It is desirable to prevent the cooling fluid from passing out of the cooling chamber along the u per surface of .lower reach of the top be t, and to prevent this from occurring on the belt at that position to flow back toward said chamber. More ositive means may also be provided for he ding the fluid back, such as a transverse wiper 47. This wiper should be of a construction not affected by the severe cold to which it is subjected so as 1to become stiff and useless. As one practica form of wiper, I have shown in Fig. 6 an inverted box filled with cotton waste or other soft material 48, with the lower side closed by a flexible material 49 such as canvas, with the said canvas in contact across the belt. The wi er box is confined between pieces bolted to t e end of the tank by bolts 50 and pressed toward the belt by a sprin 51. Such a wiper is preferabl used at bot the entrance and exit to the c amber 28 for each belt, the one forthe upper belt acti upon the up er side of the lower reach, an that for the ower belt acting upon the under side of the upper reach.

At the front or feed and of the machine, it is preferable to extend the lower conveyor forwardly in front of the upper conveyor so as to receive the article thereon before introducing it between said conveyors. At this front or feed end of the lower conve or, I preferably rovided guides 52 (Fig. for automatical y centering the article. hese guides are preferably arranged one at each edge of the conveyor, sloping inwardly toward each other in the direction of movement of the conveyor. Where the product is of regular shape, 'as with cartons 3, the guides may be so positioned that the cartons will be pushed together transversel of the belt before entry under the upper be t.

For reasons which I will presently explain, I also preferabl provide means herein for obtaining any esired ressure on the u per conveyor and there ore upon the artic e passing between the conveyors. While the weight of the upper conve or belt itself may suflice in some instances, refer to supplement that weight, which I o in the dpresent showing by use ofa lurality of space rollers 53 resting u n and supported by the upper surface of t e lower reach of the upper belt transversely thereof. Each of said rollers has longitudinally projecting central pintles 54 (see ig. 5) which enter appropriate holes in the downward] extending flange of an angle iron 55, sai iron being divided into sections which permit corres onding series of rollers to independentl ad ust themselves to articles of varying thic nesses. Each section of an le iron 55 is loosely hinged to adjacent sections, and the sections are also anarmors chored at the feed end, as by stra s 56 extending from a fixed portion of t e frame work, to anchor the rollers from moving longitudinally with the belt. This construction makes a float-in pressure with a minimum of friction. T is rollers are preferably positioned quite close together, and the first one 57, in the series, is also referably heavier than the rest to secure initial positive action thereof on the article to be refrigerated. Where occasion requires, additional weights 58 (F i 5) may be added by restin the same on the orizontal flanges of the angFe irons 55.

At the discharge end of the ap aratus, I provide, in the present showing, a ort chute 59 to a trou h 60, arranged herein in alignment with t e direction of movement of the article from the conveyors. In said trough I preferably provide a smooth sheet of ice 61, upon which the product will slide with a minimum of friction on leaving the conveyors and chute 59. This acts as a convenient form of reservoir for reception of the articles from the conve ore, and will also serve to clean the bottom 0 the article from any foreign matter.

As a preferred way of applyin my invention, I show its a plication to t e freezing of a packaged foo roduct, such as dressed, fresh fish or meat, w ereby said food product is quickly frozen in the ackage or container in which it is to be mar eted. The package preferably comprises a suitable container, such as the cardboard carton 3', which may be and is preferably waxed or otherwise rendered resistive to the passage or absorption of moisture. For further rotection, the said container should'preferab y be lined with, or the contents wrapped in an appropriate waxed paper or other moisture proof material 62. have attained satisfactory results by the use of a plaraflined vegetable parchment paper, whic does not disintegrate with exposure to moisture. The paraffin coating resists the passe e of moisture and keeps the paper from sticking to the contents. As I prefer to carry out the invention, the container 3' is preferably positioned with the cover open and the protective material 62 placed therein prior to the introduction of the food contents. With the container thus standing open, a layer of the food product is placed in the bottom thereof. If the food product, for instance. is fish fillets. as indicated in Figs. 8 to 10, the fish, either as a single fillet, if of suitable size. or a plurality of fillets if required, is laid into said container. I have endeavored to illustrate in lI 1gs. 8 to 10 of the drawings fish fillets 63 n said container, the first layer being senarated from the next layer by a moisture absorbent separator or filler 64, and so on for the several layers which the container will accommodate.

The fillets 68 are of the. usual irregular ture proof lining or protective material 62 is laid over the top and the cover closed.

Referring to Fig. 11, there are shown layers of meat chops 65, packed close together for avoiding unnecessary air s aces. The arran ement is furthermore sue that the bones of t e cho s in the lower row will preferably underlie t e meat portions of the row above, and so on, so that when pressure is applied to the package, the contents can give, thereby enabling the contents to be substantially flat against the top and bottom of the container. In this instance, also, the container is rovided with the protective lining 62, whic is closed over the top of the roduct when the container is filled, after w ich the cover of the container is closed. If desired, each chop can be wrapped in such a protective wrapping. In the same manner, steaks, chickens,

and any other food product can be similarly.

packed. Of course, if the product is one such as Hamberger steak, acking in layers may be disregarded. althoug fillers may be used to form se arable units. By filling the carton as comp etel as possible with the food roduct or overfi ling it, I insure intimacy 0 contact between the various layers or pieces of food, and between the container and the food,

and a minimum of air pockets, so that there may be uniform and ra id heat transference throu bout the mass an outward through the container itself.

After erforming the steps as above outlined, un ess the product is to be marketed very soon after freezing, the container is wrapped, as in a waxed or araflined paper 66, and this wrapping is su stantially hermetically sealed by use of hot plates or other- W186.

I then introduce the ackages into the space between the conveyor its. The filled packa may be loaded into an o n ended tray 0 suitable size, as shown at 6 Fig. 1, from which they can be readily delivered onto the upper reach of the lower conveyor belt and a vanced into the space between the two belts, arranged closely side by side and end to end, and thence carried into the freezing chamber. The speed of the conveyors may be adjusted to move the article through the freezing chamber in the length of time necessary for freezing, or the article maybe advanced into the chamber by the belts, the belts stopped and the article retained in the chamber the desired length of time when the belts can be again put in motion to deliver the article from the machine. The vertical position of the upper belt 1 having been adjusted in accordance with the thickness of the package to be treated, the

acka es as they'are carried forward by the ower It will be enga ed by the lower reach of the up r belt. T e lower belt offers a substantia y unyielding support to the package, and the upper belt is pressed downwardly on the package by its own weight and by the pressure rollers when they are used. The result is that with a product that is com arativel yielding, the mass is compacte the pr uct will tend to fill any voids in the carton, and any unevennesses are flattened out so that the product resents substantiall even flat surfaces of su stantial area, imme iately juxtaposed against the sides of the carton, with which the belts are in contact. This insures a minimum of insulating air layers or spaces, and a heat conductive contact over a substantial portion of the surface area of the block of food product, which results in eifective heat transference throughout the mass of the product, and uniform and complete freezing in the minimum length of time. The character of the package as above described retards any evaporation of the natural moisture of the food product and any tendency to a loss of moisture from the package is further retarded b the intimate contact of the belts through w ich moisture cannot pass.

Also, in the course of freezing, the food product will expand, and it is desirable that this natural expansion should, so far as possible be caused to take place in such manner as to fill out the container and yet not bulge or distort it, in order to increase the intimacy of contact between the various portions of the contents and between the contents and the container, with resulting uniformity and rapidity of freezing, and to insure that the completely frozen package shall not be bul d or distorted but s all be sightly and regu er in shape. This desirable result is insured as herein shown by the holding of the package during the freezing period between the metal belts, which press on the package at top and bottom.

I further find it advanta cons to place fillers 34 in the form of absor nt sheets between the layers of the food product in the carton, ially in the case of fish, to absorb any ee moisture which may be on the outside of the fish when inserted in the package, or which ma become freed either by g rlfssure on the fis or from any othercause.

e juice of the fish forms a medium wherein bacteria multiply more rapidly than in the fish flesh, and it is therefore desirable to avoid the presence of such free fish juice in the package. I find that an absorbent grade of cardboard answers this requirement. I may also appl a thin coating of wax to the absorbent eets, so they Wlll not adhere to the fish, and I find that the wax coating may sufliciently thin to pass moisture to the mums cardboard, where it will be absorbed, and yet prevent the sticking of the fish to the sheet. Even if the wax coating is sufliciently thick to repfl absorption, the edges of the sheets, whic will not be waxed, will absorb the moisture sufficiently to accomplish the desired purpose. The package will therefore be substantially free from free moisture, whether the product reaches the user completely frozen, -partly frozen, or entirely thawed.

I have referred in this specification to quick freezing. While I am unable to define quick freezing in terms of exact tem eratures or periods of time, the phrase will be readily understood by an one familiar with the freezing of comestib es. Freezin may take place practically instantaneous y, as by li uid air, or it may require days, as in the usua refrigeration in refrigerating rooms. In the case of such comestibles as fish or meat, for instance, if the freezing consumes any substantial period of time, the flesh. is injuriously affected and it loses its natural flavor and qualities. B quick freezing, I mean freezing in a su ciently short s ace of time so that the cells of the food product are not disru ted or broken and whereby the frozen bloc ,throughout its mass, retains its natural qualities substantially unimpaired.

As an example of a satisfactory application of my recess with the referred ap a'ra us above ascribed, I woul state that attain highly satisfactory results in freezing cartons, two inches t ick, packed asabove described with fresh meat or fish, by passing such packages through the belts of my machine, and permitting each carton or package to remain under pressure in thefreezing c amber which is 37 feet lon about one hour and a uarter, while the be ts are being s rayed wit calcium chloride of about 33 aum -maintained at an average temperature of below 0 F., the freezing fluid being supplied to the belts at the rate of about 200 gallons per minute. Of course, these figures can be varied widely according to circumstances and other freezing mediums can be used.

While I have described my process and a paratus as preferably applied to freezing t e product in the container in which it is to be marketed, I can of course apply the same to freezing the product not previously packed in the marketing package. For instance,I may apply my recess by formin the products into a bloc or slab, prefera ly covered with a wrapping such as arafiin paper, enclosed on four sides by a Frame, open at to and bottom, and delivering this framed bloc into the space between the belts, which will convey the block, in contact at top and bottom with the belts, throu h the freeiixg chamber. Aft r fr e ing, e frozenl:

can be readily removed from the open'frame and stored and marketed in any desired manner. Or I can operate direct! on the comestible or food product itsel without an wrapping, packaging or frame.

It will be noted that in my preferred method of a plying my invention, I employ packages a out two inches thick, whereby the flat sides which the belts en age are not very far apart and of course a t icker or a thinner package may be employed as desired. In order that the product to be frozen shall be quick frozen throughout its mass, the temperature of the heat conductive medium should be adjusted to the thickness of the article or package being treated as, at a given temperature, it takes longer to completely freeze a thick article or package than a thin one.

While the method is preferably employed for freezing the said method, or substantial and novel parts thereof, may advantageous- 1 be employed for quickly refrigerating or cliilling the product being treated without actually freezing it, and it is to be understood that such of my appended claims as s ecify only refrigeratin are directed to t e claimed method whet er employed for freezing or merely chilling more or less without freezin While I Ixave illustrated and described in detail an example of.a prefered manner in which I practice my process, as applied to fresh fish or meat, and have described with particularity a preferred embodiment of an apparatus which I have found useful, I do not desire to be limited to the specific details thus illustrated and described; but intend to cover all methods which fall within the spirit and scope of my invention, as defined in the following claims.

The machine or apparatus disclosed in this application is not claimed herein but is claimed in a divisional application.

Having thus described my invention, what I desire to claim is:

1. A method of packaging and preserving food which consists in first packing the food in the container in which it is to be marketed and freezing the same under pressure applied to substantial surface areas of the packed container.

2. A method of packaging and preserving food which consists in first packing the food in a container, substantially hermetically sealing said container, and freezing the same under pressure applied to substantial areas of the container to form a sealed package of frozen food.

3. A method of packaging and preservin food which consists in first packing the foo in a moisture-proof container, substantially hermetically sealing said container, and freezing said food product under pressure applied to substantial areas of the container.

4. A method of packaging and reservin food which consists in first pac ing sai food in the container in which it is to be marketed, placing said packed container between and in contact with refrigerated elements which are good heat conductors and maintaining said elements at a sufficiently low temperature to freeze said product in said container.

5. A. method of packaging and preserving food which consists in first packing the same in a container for delivery,placing at least two sides of said packed container in contact with refrigerated elements which are good heat conductors, niaintainin said elements pressed firmly in contact wit said container and maintaining said elements at a sufiiciently low temperature to freeze said product in said container.

6. A method of packing and preservin food which consists in first packing said foo in a container for delivery, applying pressure to said container to press upon opposed surfaces of said packed food and freezing said food in said container by conduction uniformly applied over substantially the entire area of said com ressed surfaces.

7. A method 0 packa ng and preserving food which consists'in rst packing a plurality of layers of the same in a container with a moisture absorbent filler between said layers, and freezing said food in the contamer under pressure applied to substantial surface areas thereof.

8. A method of packaging and preserving food which consists in first packing the same in a container with a moisture absorbent filler between each layer, said filler bein surface coated to prevent sticking to the pro uct, and freezing said food in said container under pressure applied to substantial surface areas thereof.

9. A method of freezing a food product which consists in firmly engaging the same under predetermined pressure on two sides between heat conductive members and flowing a refrigerating medium over the outer faces of said members while shielding the food therefrom.

-10. The process of pre aring a food product which consists in pac 'ng the product in the carton in which it is to be marketed and quick freezing said food product in said carton, by conduction applied over substantial surface areas of said carton.

11. The process of pre aring a food product Which consists in pac ing the roduct in the carton in which it is to be mar eted, substantially hermetically sealing the packed carton, and quick freezing the product in said sealed carton, by conduction applied over substantial surface areas of said carton.

12. The process of pre aring a food product which consists in packing the roduct in the carton in which it is to be mar eted, surrounding the roduct in the carton with a moisture-proo lining, substantially hermeti cally sealing the packed carton, and quick freezingi1 the product in said sealed carton.

13. T e process of pre aring a food product which consists in ac ing the product in the container in whic it is to be marketed, placing the packed container between heat conductive members which engage the same over a substantial portion of its surface area, and maintaining said members at a temperature sufficiently low to quick freeze the product in said packed container.

14. The process of pre aring a food prodnot which consists in packing the product in a container, placing the packed container between heat conductive members which en gage opposite faces thereof, sub'ecting the packed container to pressure, an maintaining said members at a temperature sufliciently low to quick freeze the product while under pressure.

15. A process of preparing a food product which consists in packing the same in acontainer, filling said container so as to insure a minimum of air voids, pressing together opposed surfaces of said packed container further to compact said product and eliminate air voids and simultaneously freezing said product into a frozen block in said container.

16. A process of preparing a food prodnot which consists in packing the same in a container, placing at least two sides of said packed container in contact with flat heat conductive members, maintainin said surfaces firmly in contact with sai container and maintaining said members at a sufficiently low temperature to quick freeze said product in said container.

17. A process of preparing a food product which consists in packagmgthe product in a package for delivery, applying pressure to sa1d ackage to flatten t e opposlte surfaces of said product, and quick freezlng said packa (1 product by conduction-unlformly app ied over substantially the entire area of said flattened surfaces while said pressure is maintained..

18. A process of preparing a food product which consists in packagln the same m a package for delivery, applying continued pressure to said package to flatten the product, and simultaneously freezing and product in said packa e by conduction uniformly applied over su stantially the entire flattened surfaces of said product.

19. The method of freezing food products which consists in passin the food through a. refrigerating zone w 'le applying heat conductive members to opposite sides thereof, subjecting said conductive members to a bath of refri rating medium from which the food is shielded, and simultaneously applying lplressure to said food.

20. e method of treating a food product which consists in forming the same into a block, passin the block through a refrigerating zone w ile applying heat conductive members to the opposite sides thereof, and subjecting said members to the action of a refrigeratin medium while shielding the block there rom.

21. The method of treatin a food product which consists in passing te roduct past a refrigeratin medium whic simultaneously extracts eat from opposite sides thereof and at the same time applying pressure to the food and shielding it from the refrigerating medium.

22. The method of packin and preserving food which consists in rst packagin the food, then passing said package throug a refrigerating zone in which heat conductive members are applied to opposite sides of the package, and sub'ecting said conductive members to a re rigerating medium while shieldin the package therefrom.

23. The met od of refri rating and [areserving food products whic consists in packagin the'same, passing the packages past a re igerating medium which simultaneously extracts heat from two sides thereof, and at the same time applying pressure to the package and shielding the package from the refrigerating medium? 24. The method of packaging and preserving food which consists in first packaging the food, then passing the package through a refri erating zone m which heat conductive mem era are applied to op site sides of the package, and su jecting sai conductive members to a refrigeratin medium while shielding the package there rom and simultaneously applying pressure to said packai1 a 25. e method of packaging and preserving food products which consists in first gackaging the products in a container for elivery and passing the container past a refri erating medium which extracts heat simu taneously from twosides thereof while shielding the container from said refrigeratin medium. v

26. he method of pre arin a food product which consists in pac 'n t e same in the container in which it is to e marketed, engaging the bottom surface of the acked con tainer by a heat conductive mem r, engaging the top surface of the container by a second heat conductive member, and subjecting the packed container to afreezin temperature through the medium of sai engagi heat conductive members for an interval su ficient completely to freeze said product into a frozen b ock in said container.

t In testimony whereof, I have signed my name to this s 'fication.

. ENCE BIRDSEYE.

DISCLAIMER 1,773,079.-Clarmce Birdseye, Gloucester, Mass. METHOD r011 PREPARING FOOD PRODUCTS. Patent dated Au ust 12, 1930. Disclaimer filed March 17, 1943, by the assignee, General oods Corporation. Hereby enters this disclaimer to claims 1 to 9, inclusive, 14, 15, and 16, and 18 to 26, inclusive, in-said specification.

[Oficial Gazette April 13, 1943.] 

